Séminaires du
Département d'Astrophysique, Géophysique et Océanographie

Mardi 27 août, 16h00

Salle de réunion AGO (local -1/14)
Institut d'Astrophysique et de Géophysique
Quartier Agora, Allée du 6 Août, 19C, B-4000 Liège 1 (Sart-Tilman)

Clusters of primordial black holes

Konstantin Belotsky

Primordial black holes (PBHs) are a well-established probe of new physics in the very early Universe. I am going to discuss the possibility of PBH agglomeration into clusters that may have several interesting observable features. The clusters can form due to the production of closed domain walls in the natural and hybrid inflation models whose subsequent evolution leads to PBH formation. Such model inherits all the advantages of uniformly distributed PBHs -- it can possibly explain the early formation of quasars and the rate of binary black hole mergers registered by LIGO/Virgo, these clusters can contribute to the reionization of the Universe. The model also potentially alleviates the existing constraints on the abundance of uniformly distributed PBH, thus allowing clusters of PBH to be a viable dark matter candidate. I am going to show that most of the existing constraints on uniform PBH density should be reconsidered in the case of PBH clustering.